River Improvements

River Improvements at Bourne End Recreation Ground

This project was one of three habitat enhancement Projects on the Wye in 2016 which followed a successful Revive the Wye bid for funding via the South Chilterns Catchment Partnership. The work at Bourne End Recreation Ground was project managed by the Chilterns Chalk Streams Project on behalf of RTW, working in partnership with Wooburn and Bourne End Parish Council, Chiltern Rangers and the Environment Agency.
Before the main project work could commence, RTW conservation volunteers cleared the bankside of excessive vegetation and the Parish Council removed the remains of an old fence. Local contractor Bartletts were engaged to carry out riparian tree work to open up the over-shaded river to more daylight.

The project’s objective was to enhance the river’s habitat along a 150m section of the Wye adjacent to the Recreation Ground. The river there had become degraded through past management practices which had led to it becoming straightened, over-wide and heavily shaded by bankside trees. As a result it lacked the habitat features normally associated with healthy chalk streams.
Significant habitat improvements for fish and other wildlife were achieved by a combination of tree management work and the installation and planting of a variety of Large Woody Debris (LWD) and berm structures to narrow this previously over-wide and low flow section of river.
Over 40 volunteers from RTW, Bucks New University, the River Chess Association and the local community were involved over a period of two days.
Read More and see photos

Improvements to the Back Stream at Bowden Lane

This project has been delivered in several phases as funding has been awarded.
It was also initiated with Catchment Partnership funding allocated following a Revive the Wye proposal and funding from the Thames Water and Wild Trout Trust supported River & Wetlands Community Days fund. The project was managed by Chiltern Rangers.
It focussed on a 40m stretch of Wye’s Back Stream adjacent to the Funges Meadow Nature Reserve. The project began by hiring tree surgeons to undertake riverside tree work (ivy trimming, felling and pollarding). This allowed more light into the stream to encourage plants to grow and bind up. The arisings (branches & logs) were used to create the in-stream structures. The rest were stacked in the nature reserve as a habitat pile for wildlife.
Under a Floods Defence Consent from the Environment Agency, two berms and three deflectors (to create riffles) were installed in the stream. A stream dipping station accessible from the nature reserve was created.

Gravel being moved into Wye at Bowden Lane

Replacement board walk

Silt was removed from the central river channel to diversify the stream structure and used to help create marshy wetland marginal habitat within the berms. Approx 40 tonnes of gravel was moved by hand with the help of numerous volunteers and corporate teams on ‘Be a Ranger Days’ into the stream to encourage invertebrate populations and create better spawning habitat for fish such as Brown trout.
Additional funding obtained later, following a separate RTW bid to the River & Wetlands Community Days Fund prepared by Chiltern Rangers, enabled the planting of the banks and berms with suitable native plants, removal of litter, and the installation of bat and bird boxes. This funding, supplemented by some (S.106) funding from Wycombe District Coucil, also helped to pay for a replacement non-slip board walk from Bowden Lane into the nature reserve.

All this was work was achieved with the help of a large number of volunteers (193 volunteers giving approximately 900 hours of time) from the Chiltern Rangers, Chilterns Chalk Streams Project, Revive the Wye, Berkshire College of Agriculture, Friends of Marsh & Micklefield Woods, Foundation for Water Research, Buckinghamshire New University, Green Thursday Conservation Volunteers, Queen Mary University of London, Thames Water staff and staff from a local pharmaceutical company on ‘Be a Ranger Days’.

Wooburn Park and Brookbank

In recent years Revive the Wye has conducted a number of volunteer conservation events along these attractive stretches of the Wye through Wooburn. They have involved installing a number of in-river deflectors to narrow the channel and to speed water flow, which helps to wash-out the build-up of silt. The aim is to improve the channel for spawning trout and other fish and for a range of invertebrates. Some of these events have been used as volunteer training exercises and also to encourage the awareness and engagement of the local community in RTW’s work.

Staff from the Chilterns AONB Office installing deflectors at Brookbank on a very cold training day.

In 2016, some of the funding made available through the local catchment partnership was used to undertake bank-side tree works to reduce shading and used to replace 5 old deflectors which had been placed in the river some years before. The timber used to make the deflectors was surplus material from the sites where tree work was conducted during the 2016 project programme.
This was undertaken with help of students from BCA, Thames Water staff and staff from a local pharmaceutical company on a ‘Be a Ranger Day’.

Surveying and monitoring river improvement projects

An important aspect of the joint work of RTW in association with the Environment Agency and the wider local Catchment Partnership is to monitor the impact of river improvement projects on the ecological quality of the river. This is carried out in a number of ways. For example, a trout survey using the redd methodology was conducted along the Bourne End Recreation Ground stretch of the river in December 2015, before the 2016 improvement work commenced. A repeat survey was due to be carried out in December 2016. It is anticipated that redd numbers will increase in this section as a consequence of increase holding habitat for adult fish, greater scour of gravels and the recently installed fish passes up and downstream of the site See River Flow Modification. Fixed point photography commenced at the site in June 2015 and is being repeated on a frequent basis by volunteers. The objective of this is to assess the development of habitat (particularly the marginal shelves) over time.

All the 2016 improvement project sites are now subject to riverfly monitoring  by trained RTW volunteers. The data will be used to determine what impact the works have had on riverfly abundance and diversity.

Next  Habitat improvements